Assuntos
Betacoronavirus , Infecções por Coronavirus , Saúde Global , Internacionalidade , Colaboração Intersetorial , Pandemias , Pneumonia Viral , Mudança Social , COVID-19 , Atenção à Saúde/organização & administração , Equipamentos e Provisões/provisão & distribuição , Governo , Humanos , Indústrias/organização & administração , Equipamento de Proteção Individual/provisão & distribuição , Preparações Farmacêuticas/provisão & distribuição , Saúde Pública , Pesquisa/organização & administração , Alocação de Recursos , SARS-CoV-2 , Populações VulneráveisRESUMO
The Bland-Altman (BA) and percentage error (PE) methods have been previously described to assess the agreement between 2 methods of medical or laboratory measurements. This type of approach raises several problems: the BA methodology constitutes a subjective approach to interchangeability, whereas the PE approach does not take into account the distribution of values over a range. We describe a new methodology that defines an interchangeability rate between 2 methods of measurement and cutoff values that determine the range of interchangeable values. We used a simulated data and a previously published data set to demonstrate the concept of the method. The interchangeability rate of 5 different cardiac output (CO) pulse contour techniques (Wesseling method, LiDCO, PiCCO, Hemac method, and Modelflow) was calculated, in comparison with the reference pulmonary artery thermodilution CO using our new method. In our example, Modelflow with a good interchangeability rate of 93% and a cutoff value of 4.8âLâmin, was found to be interchangeable with the thermodilution method for >95% of measurements. Modelflow had a higher interchangeability rate compared to Hemac (93% vs 86%; P = .022) or other monitors (Wesseling cZâ=â76%, LiDCOâ=â73%, and PiCCOâ=â62%; P < .0001). Simulated data and reanalysis of a data set comparing 5 CO monitors against thermodilution CO showed that, depending on the repeatability of the reference method, the interchangeability rate combined with a cutoff value could be used to define the range of values over which interchangeability remains acceptable.
Assuntos
Débito Cardíaco/fisiologia , Termodiluição/métodos , França , Humanos , Monitorização Intraoperatória/métodos , Monitorização Intraoperatória/normas , Artéria Pulmonar/diagnóstico por imagem , Artéria Pulmonar/fisiopatologia , Valores de Referência , Reprodutibilidade dos TestesRESUMO
Blood glucose and its variability of is a major prognostic factor associated with morbidity. We hypothesized that intravenous microdialysis incorporated in a central venous catheter (CVC) would be interchangeable with changes in blood glucose measured by the reference method using a blood gas analyzer. Microdialysis and central venous blood glucose measurements were simultaneously recorded in high-risk cardiac surgical patients. The correlation between absolute values was determined by linear regression and the Bland-Altman test for repeated measurements was used to compare bias, precision, and limits of agreement. Changes in blood glucose measurement were evaluated by four-quadrant plot and trend interchangeability methods (TIM). In the 23 patients analyzed, the CVC was used as part of standard care with no complications. The correlation coefficient for absolute values (N = 99) was R = 0.91 (P < 0.001). The bias, precision and limits of agreement were - 9.1, 17.4 and - 43.2 to 24.9 mg/dL, respectively. The concordance rate for changes in blood glucose measurements (N = 77) was 85% with the four-quadrant plot. The TIM showed that 14 (18%) changes of blood glucose measurements were uninterpretable. Among the remaining 63 (82%) interpretable changes, 23 (37%) were interchangeable, 13 (20%) were in the gray zone, and 27 (43%) were not interchangeable. Microdialysis using a CVC appears to provide imprecise absolute blood glucose values with risk of insulin misuse. Moreover, only one third of changes in blood glucose measurements were interchangeable with the reference method using the TIM.
Assuntos
Análise Química do Sangue/métodos , Glicemia/metabolismo , Microdiálise/métodos , Monitorização Intraoperatória/métodos , Idoso , Análise Química do Sangue/estatística & dados numéricos , Procedimentos Cirúrgicos Cardíacos , Cateterismo Venoso Central , Cateteres Venosos Centrais , Estudos de Coortes , Feminino , Humanos , Masculino , Microdiálise/instrumentação , Microdiálise/estatística & dados numéricos , Pessoa de Meia-Idade , Monitorização Intraoperatória/instrumentação , Monitorização Intraoperatória/estatística & dados numéricos , Estudos ProspectivosRESUMO
PURPOSE: The main goal of this study was to assess whether maximal fluid infusion improves both oxygen delivery (DO2) and micro-circulatory parameters during hemodilution. The secondary objective was to assess the ability of baseline micro-circulatory parameters to predict oxygen consumption (VO2) response following fluid infusion. MATERIALS AND METHODS: In a postoperative cardiac ICU, patients received repeated fluid infusion until stroke volume (SV) was maximized. Before and after each fluid expansion, macro- (DO2, VO2) and micro-circulatory oxygenation parameters were recorded [central venous oxygen saturation (ScVO2), blood lactate, difference in veno-arterial carbon dioxide tension (P(v-a)CO2), somatic and cerebral oxygen saturation (rSO2)]. Patients were classified as VO2-Responders or VO2-Non-Responders according to an increase in VO2 above or below 15%, respectively. RESULTS: After maximal fluid infusion, all patients showed improved macro- and micro-circulatory oxygenation parameters, but VO2-Responders had lower values (especially for ScVO2 and cerebral rSO2). Only baseline ScVO2 and cerebral rSO2 were useful to predict the VO2 response to maximal fluid infusion (ROCAUC 0.80 (95% CI: 0.54-0.95, P=0.012) and 0.83 (95% CI: 0.57-0.96, P=0.001). CONCLUSIONS: Maximal fluid infusion improves macro- and micro-circulatory oxygenation parameters. For VO2-Responders, only ScVO2 and cerebral rSO2 could serve as markers of tissue hypoxia.
Assuntos
Procedimentos Cirúrgicos Cardiovasculares , Estado Terminal/terapia , Hidratação , Hipovolemia/terapia , Oxigênio/sangue , Idoso , Área Sob a Curva , Feminino , Hemodinâmica , Humanos , Masculino , Projetos Piloto , Período Pós-Operatório , Estudos ProspectivosRESUMO
OBJECTIVES: To assess the trending ability of calibrated pulse contour cardiac index (CIPC) monitoring during haemodynamic changes (passive leg raising [PLR] and fluid loading) compared with transpulmonary thermodilution CI (CITD). METHOD: Seventy-eight mechanically-ventilated patients admitted to intensive care with calibrated pulse contour following cardiac surgery were prospectively included and investigated during PLR, and after fluid loading. Fluid responsiveness was defined as a≥15% CITD increase after a 500ml bolus. Areas under the empiric receiver operating characteristic curves (ROCAUC) for changes in CIPC (ΔCIPC) during PLR to predict fluid responsiveness and after fluid challenge to predict an increase at least 15% in CITD after fluid loading were calculated. RESULTS: Fifty-five patients (71%) were classified as responders, 23 (29%) as non-responders. ROCAUC for ΔCIPC during PLR in predicting fluid responsiveness, its sensitivity, specificity, and percentage of patients within the inconclusive class of response were 0.67 (95% CI=0.55-0.77), 0.76 (95% CI=0.63-0.87), 0.57 (95% CI=0.34-0.77) and 68%, respectively. Bias, precision and limits of agreements and percentage error between CIPC and CITD after fluid challenge were 0.14 (95% CI: 0.08-0.20), 0.26, -0.37 to 0.64 l min(-1)m(-2), and 20%, respectively. The concordance rate was 97% and the polar concordance at 30° was 91%. ROCAUC for ΔCIPC in predicting an increase of at least 15% in CITD after fluid loading was 0.85 (95% CI: 0.76-0.92). CONCLUSION: Although ΔCIPC after fluid loading could track the direction of changes of CITD and was interchangeable with bolus transpulmonary thermodilution, PLR could not predict fluid responsiveness in cardiac surgery patients.
Assuntos
Débito Cardíaco , Procedimentos Cirúrgicos Cardíacos/métodos , Idoso , Idoso de 80 Anos ou mais , Área Sob a Curva , Calibragem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Monitorização Fisiológica , Assistência Perioperatória , Estudos Prospectivos , Curva ROC , Reprodutibilidade dos Testes , TermodiluiçãoRESUMO
Smokers are exposed to early endothelial dysfunction. This microcirculatory damage can be demonstrated by near-infrared spectroscopy (NIRS). The aim of this study was to compare microvascular reactivity by NIRS during a dynamic vascular occlusion test in healthy smokers and nonsmokers volunteers. Twenty healthy volunteers (10 men, 10 women), aged from 22 to 38 years old, were included after approval of the local Ethics Committee and divided into two groups: smokers (n = 10) and nonsmokers (n = 10). Tissue oxygen saturation (StO2) was measured at the level of each individual's calves during an ischemia and reperfusion test. In addition, during the ischemia phase, the slope of decline in StO2 was determined. Therefore, for each group, we were able to deduce the speed of desaturation (ΔStO2/ischemia time). The same was applied for resaturation rates during the reperfusion phase (ΔStO2/reperfusion time). StO2 values were comparable at all experimental steps between smokers and nonsmokers. During the vascular occlusion test, rates of desaturation were the same between smokers and nonsmokers [respectively 3.7%·min(-1) (range 2.5-12.6) and 3.7%·min(-1) (range 1.8-15.1); p = 0.50]. It was the same for the rate of resaturation [smokers 30.4%·min(-1) (range 14.2-51.6) and nonsmokers 30.5%·min(-1) (range 18.6-44.5); p = 0.82]. NIRS study of microvascular reactivity during a dynamic vascular occlusion test did not reveal any difference between smokers and nonsmokers. Therefore, NIRS could not be sensitive enough to highlight endothelial dysfunction in healthy subjects exposed to tobacco smoke.